Support casing for a boring head

ABSTRACT

Drilling apparatus for installing casing while drilling in which a mobile head is connected to the lower end of a casing by bearing means. A drilling pipe string extends through the casing and is coupled to the casing at the upper end. A drilling bit is fixed to the lower end of the drill pipe and includes a plurality of retractable arms which cooperate with recesses in the mobile head to rigidly connect the drilling bit to the mobile head.

[ Aug. 26, 1975 Djurovie 1 SUPPORT CASING FOR A BORING HEAD [75]Inventor: Branko Djurovic, Clichy, France [73] Assignee: Societe Anonymeof Compagnie Francaise des Petroles, Paris, France [22] Filed: Dec. 3,1973 [21] Appl. No: 420,838

[30] Foreign Application Priority Data Dec. 6, 1972 France 1. 72143343[52] U.S. Cl. 175/171; 175/101; 175/103; 175/173; 175/258; 175/261 [51]Int. Cl. E21B 43/01; E218 7/12 [58] Field of Search 175/92, 101, 103,107, l75/l7l, 173, 257, 258 260, 26l, 62,171

[56] References Cited UNITED STATES PATENTS 1 295 969 3/1919 Carmichael.1 175/260 2239996 4/1941 Chappell 2. 175/261 3.199.613 8/1965 Malott cta]. 175/257 X 3,216 512 11/1965 0111616 175/171 x 3.262508 7/1966 PriCC175 171 x 3.491342 1/1970 0611166111 et 111W. 175/171 x 3519.071 7/1970Word 1. 175/171 x 3.552.508 1/1971 Brown 175/258 3552.509 1/1971 Brown 1v A t w 175/2511 3,703,212 11/1972 Abrahams.... 175/171 x 3,73211435/1973 .lOOSSC 4. 175/101 x Primary Examiner-David H. Brown Attorney,Agem, 0r F1'rmSughrue. Rothwell, Mion, Zinn and Macpeak 13 Claims, 15Drawing Figures PATENTED AUS 2 6 i975 PATENTEU 2 1975 SILET 5 BF 5 gig gg 5 22a 22 v g ii um fi m "Ea. .i 22

SUPPORT CASING FOR A BORING HEAD The invention relates to a supportcasing apparatus for a drilling head applicable to all earth boring workand in particular to under-water petroleum drilling.

The need to protect bore holes and in particular petroleum drill holesleads to the use of a casing placed in position after drilling apre-hole. For this purpose. the first drill hole is enlarged by means ofa suitable tool and then after removal of this tool the casing islowered into the hole. All these operations are lengthy and costly. Theyare still more so in the case of an underwater petroleum drill hole.Moreover, when drilling is carried out in soft ground, it is not unusualfor cave-ins to occur between the moment of drilling and the location ofthe casing, thus necessitating further work.

According to the present invention there is provided a support casingapparatus for a drilling head comprising (1) a casing wherein the headis connected to the casing by a bearing connecting means permitting freerotation of the head about its axis, (2) first means for coupling thehead to a lower portion of a pipe string carrying a drilling tool todrive the head, and (3) a second coupling means located at the upperportion of the casing for rigidly attaching it to a pipe string.

It is therefore sufficient for placing the casing in position in asingle operation to select a drilling head and a drilling tool, a bitfor example. suitable for the soils to be encountered. The combinationof the bit, the head, and the casing fixed on its orientation relativeto the soil forms in itself both a drilling tool of sufficient diameterfor the introduction of the casing and a pipe for protection of thedrill hole in which muds and drilled soil may subsequently be raised.Thus all the intermediate operations of lowering and lifting the tool,enlarging the first drill hole, and placing the casing in position areavoided.

To facilitate the actual drilling in the case of unforeseen change ofthe tool without having to raise the easing fitted with its drillinghead, the coupling means of the head relative to the drilling tool maybe arranged so that the head is set back relative to the tool and meansmay be provided on the upper part of the casing to rigidly connect thelatter to guide means used for recovery of the original drilling toolafter the casing has been placed in position and to guiding means forcoupling the upper end of the casing to the pipe string.

The present invention will be more fully understood from the followingdescription of an embodiment thereof, given by way of example only, withreference to the accompanying drawings, wherein:

FIGS. la and lb are diagrammatic views. partially in axial section, ofan embodiment of easing apparatus according to the invention andincluding means for coupling to pipe string and to a bit;

FIG. 2 is an axial section of apparatus for control of means forcoupling to the pipe string;

FIG. 3 is a section along the line Ill-III of FIG. In;

FIG. 4 is a section along the line IV-IV of FIG. In;

FIG. 5 is a section along the line V-V of FIG. Ia,-

FIG. 6 is a sectional view of a detail of bearing means connecting thedrilling head to the casing;

FIG. 7 is a view from below the head in the drilling position;

FIGS. 8 8s 9 are sections along the lines VIII-VIII and IXIX of FIG. 7;

FIG. 10 is a section along the line X-X of FIG. lb;

FIG. 11 is a perspective view ofa cutaway portion of a modification ofthe head;

FIG. 12 is a diagrammatic view of the outer portion of a bitco-operating with the head of FIG. 11;

FIG. 13 is a general view of the casing separated from the drillingtool, and

FIG. I4 is a diagrammatic representation of the well of a drillingbarge.

In FIGS. la and lb, meeting along cut line I, it will be seen thatcasing assembly 2 comprises a pipe or casing 3 provided at its lowerportion with a head 4 and a bearing means 5, a detail view of which isgiven in FIG. 6. At its upper portion, casing 3 is shaped to receive anassembly 6 including a first coupling means having latches 8 and a plate27 known as a base plate and supporting a guide assembly 7 acting asguide means for the reintroduction of bit 28-for example after toolchanging to recommence drilling.

The coupling means of assembly 6 may be a conventional hydraulicallycontrolled connector. To clarify the drawing, the latches 8 of thecoupling means have been shown symbolically. As the conventionalmechanism may be of any known type, it will not be further described.Only control pipe 37, which is used for unlocking the coupling means,has therefore been shown in the drawing. In the absence of pressure incontrol pipe 37, latches 8 extend into one of a plurality of circulargrooves 3a in the upper portion of easing 3 rigidly attaching assembly 6to the casing 3.

The upper end of assembly 6 is welded along the whole of its peripheryto a castillated member 9, shown in plan in FIG. 3 and from below inFIG. 4. The weld line has been shown at 40 and 41. Member 9 has acentral aperture which is castellated. the castellations or splinesengaging in three longitudinal grooves 420 in a threaded pipe 42.Threaded pipe 42 is attached to pipe string 45 by upper joint 38 andlower joint 26, shown in FIG. 2, so that rotation of assembly 6 lockedon casing 3 relative to pipe string 45 is prevented.

The position of castellated member 9 on threaded pipe 42 is determinedby a member 10, FIG. 5. having a central threaded aperture. In order torigidly attach pipe string 45 to assembly 6, it is sufficient to screwmember 10 onto threaded pipe 42 to the required height, i.e. to a heightpermitting latches 8 to penetrate one of the circular grooves 3a in theupper portion of easing 3 when castellated member 9 rests on member 10,and then to fix castellated member 9 on member 10.

In order to facilitate screwing of member 10 onto threaded pipe 42, acertain number of threaded holes are provided in the peripheral surfaceof the member 10 permitting insertion of a bar having an end threadedwith the same thread as these holes. After member 10 has been brought tothe selected level and the above bars have been removed castellatedmember 9 is attached to member 10. For this purpose. castellated member9 is provided with three openings 9b allowing passage of the shanks ofbolts 43 therethrough and into threaded holes 10b of member I0, openings9b being of sufficient angular dimensions for at least one threaded hole10b to be exposed to receive a bolt 43 whatever the angular position ofmember I0 relative to castellated member 9. The heads of the bolts 43bear on the bases of grooves 9c bordering the openings 9b. A sealbetween the interior of easing 3 below castillated member 9 and theexternal environment is provided by annular elastic seals 44 in twocircular grooves I01." in member I mating with two correspondingcircular grooves M in castellatcd member 9.

The upper portion of threaded pipe 42 is connected to rod string 45 bylower joint 26, FIG. 2, which has an internal sleeve 36 normallyretained by shear screws or pins 46. The internal sleeve 36 blocks apassage 26a extending control pipe 37, seals 53 ensuring the fluidtightness of the sleeve. The upper joint 38 rigidly attaches the lowerjoint 26 to rod string 45.

The upper portion 360 of internal sleeve 36 acts as a seat for a closuremember 39 when the latter descends through rod string 45 to cause theautomatic unlocking of assembly 6. When a frusto-conical portion 39a ofclosure member 39 rests on seat 360. the pressure inside rod string 45increases until shear pins 46 are broken and internal sleeve 36 isdriven until it comes to rest on seat 26b provided in lower joint 26.When internal sleeve 36 rests on seat 26b, internal sleeve 36 frees thepassage 26:: and thus causes the pressurisation of control pipe 37causing unlocking of latches 8 of assembly 6. This action is sufficientto disconnect assembly 6 from the upper portion of easing 3.

The lower portion of threaded pipe 42 is connected to the drillingattachment. figures Ia and lb, by a pipe string comprising a stem 11supporting a turbine 12, the shaft 13 of which drives bit 28 through adiminisher 14.

In the embodiment illustrated, the bit 28 includes three retractablearms 15 which are also visible in FIG. I0. The double-ended arrows inFIG. I0 are intended to illustrate the retractability of the retractablearms IS. The retractable arms I are driven by the bit 28 as it rotates,permitting angular coupling of the bit 28 to the head 4 by any knownmeans. The head 4 may be of any type and have soil attacking zones 4a,FIGS. 7 to 9, of any suitable form, for example as shown in FIGS. 8 and9. As shown in FIG. 10, the means for coupling bit 28 to head 4 mayconsist of recesses 4b provided in the head 4 and of the retractablearms of bit 28 which enter these recesses.

The head is preferably mounted as shown in FIG. 6, in which the lowerend of easing 3 comprises a lower housing for insertion of bearing meanssuch as ballbearings 16 bearing directly on the upper portion of head 4and a lateral housing for bearing means such as ball-bearings 17retained by a ring or annular member I8. Ring I8, rigidly attached tohead 4 by screws 19, ensures with seals 20 and 21. which may for examplebe lip seals. the fluid tightness of bearing means 5.

In the modified head 33, a portion of which is illustrated in FIG. ll.instead of the straight-edged recesses 4b of head 4, FIGS. 7 to I0,recesses 29 are provided. one of the edges 30 of which is extended by aramp 3i and the other edge 32 of which extends up to the ramp 3i of thepreceding recess 29.

Because of the relatively large number of recesses and the arrangementof the ramps. the structure of head 33 provides the advantage of beingable to receive shoulders 34 of bit 35 shown in FIG. 12 and easilyguiding them to the bases of recesses 29. A quick. strong. and efficientjoint is thus formed, since it is sufficient for shoulders 34 to impingeeither laterally on an edge 32 or vertically on a ramp 31 in order forthe shoulder 34 to be guided to the base of recess 29.

When it is required to drill in an under-water environment with theabove described apparatus. easing 3 is provided with its bearing means 5and head 4 (or 33) and is lowered by means of derrick 47, FIG. 14, androtary table 49 mounted on the upper deck 48 of the drilling barge 22.The rotary table 49 is used to form the overall casing 3 progressivelyby adding additional sections of easing as each section is sunk into thesoil 25. The length of easing 3 may vary depending on the nature of thesoil 25 in which drilling is to be carried out. Base plate 27, on whichguide assembly 7 rests, may be fitted on the retractable floor plate 51of the lower deck 50 inside wall 220. Attachment of base plate 27 tocasing 3 is effected by simple application of profile 27a of plate 27 toprofile 3b of casiing 3, followed by clamping, seals 52 being providedbetween these elements. For this purpose. the casing 3 is lowered bymeans of a handling pipe until profile 3b of the casing, FIG. la,reaches the level of profile 27a of base plate 27. The casing 3 is thenrotated until it reaches the position shown in FIG. la, in which thebase plate 27 is locked on profile 3b of the casing, and the handlingpipe is raised. It will be noted that in addition to guide assembly 7,plate 27 bears arms 23, FIG. I3, at the ends of which sonar reflectors24 are provided for facilitating access to the well head-at a toolchange for example.

When casing 3, still retained by the derrick 47, has been thus equipped,the drilling attachment comprising the stem 11, the turbine 12, theshaft 13, the diminisher I4, and the bit 28 (or 35) is lowered intocasing 3. Thus the bit 28 (or 35) is attached to diminisher l4 driven byturbine 12 connted to stem 11, and the drilling attachment is loweredprogressively into casing 3 until the bit 28 (or 35) reaches head 4 (or33) and effects bit head interlocking as already described, interlockingbeing carried out either by engaging retractable arms 15 in recesses 4b,FIG. 10, or bringing shoulders 34 into contact with the bases ofrecesses 29, FIG. 11. As described above, threaded pipe 42 is thenplaced in position. member 10 is then screwed onto the rod to act as anattachment means for castellated member 9 rigidly attached to assembly6, which in turn is locked onto the upper portion of easing 3 aftermounting of lower joint 26 and upper joint 38. It is clear that thelength of the drilling attachment is such that when hit 28 (or 35) isengaged with head 4 (or 33) and member 10 has been screwed to thenecessary height on threaded pipe 42, latches 8 fit into circulargrooves 3a so that casing 3, the drilling attachment, and the pipestring 45 which is subsequently attached) form an assembly which can belowered after complete opening of retractable floor plate 51 until thebit 28 (or 35) reaches the drilling location.

If the nature of the soils requires it. a plate similar to base plate 27may optionally be lowered in advance to the actual point of drilling.and this plate may also carry sonar reflectors facilitating the start ofthe drilling.

When turbine 12 drives the diminisher I4 and therefore hit 28 (or 35only head 4 (or 33) is rotated pipe string 45 and easing 3 beingsubjected only to a lowering motion. During this part of the drilling.the mud rises between the casing and the soil.

If for some reason or other the drilling attachment comprising elements11 I4 and 28 needs to be raised before casing 3 has been completely sunkinto the ground. it is sufficient. after having caused the retraction ofretractable arms 15, where bit 28 is being used, to introduce closuremember 39 into the duct of pipe string 45 to cause breakage of shearpins 46. the drop of internal sleeve 36, and the application of pressureto control pipe 37, causing the withdrawal of latches 8. Where bit 35 isused, the process is obviously analogous. The rod string may then beraised with the drilling attachment and, after possible changing of thetool, the assembly may be lowered after replacement of lower joint 26and its internal sleeve 36. As the apparatus for guidance by sonarreflectors 24 may be of any conventional type, it has not beendescribed, and it is evident that, although the preferred embodiment ofthe invention includes such means, other types of conventional guidemeans, such as anchor cables, could alternatively be used. When the bitreaches guide assembly 7, it is sufficient to lower the pipe stringuntil the bit and the head interlock for assembly 6 to again be in thelocking position on the upper portion of casing 3. Drilling isaccomplished jointly by the bit and the head and is continued until thecasing has been completely sunk in so that base plate 27 reaches itsfinal operating position. Depending on the bit used, drilling maybepursued immediately without raising the drilling attachment, or else thetool changed as described above.

It is evident that when drilling is shallow and the nature of the groundlends itself to it, member 10 may be dispensed with, and threaded pipe42 may be replaced by a simple grooved rod, the castellated member 9being rigidly attached to the said rod or otherwise. However, in othercases, die embodiment described is particularly effieient, whatever maybe the soils en countered and the vibrations due to the rotation of thetool.

What we claim is:

l. A support casing apparatus for a drilling head comprising a casing,wherein the head is connected to the casing by a bearing connectingmeans permitting free rotation of the head about its axis, first meansis provided for coupling the head to a lower portion of a rod stringcarrying a drilling tool to drive the head, the casing has at its upperportion second coupling means for rigidly attaching it to a pipe string,the second coupling means include a castellated member and in the pipestring includes a pipe with longitudinal grooves in which thecastellations of the castellated member are engaged, the rod beingattached at its lower portion to a stem supporting a turbine for drivinga drilling tool and at its upper portion to a joint of the upper portionof the rod string, the said joint being provided with a sleevecontrolled by a valve and with a pipe connected to and for causingunlocking of the second coupling means, such that operation of thesleeve causes release of the pipe string from the casing.

2. Apparatus as claimed in claim 1, wherein the castellated member isrigidly attached to a means for locking the castellated member on thegrooved rod.

3. Drilling apparatus comprising:

a. a mobile drilling head having bearing recesses in its inner wall;

b. an immobile casing extending upwardly from said mobile drilling head;

c, a drilling bit;

d. a pipe string rigidly connected to said drilling bit and extendingupwardly through said immobile casing e. means for coupling the upperportion of said immobile casing to said pipe string;

f. a plurality of retractable arms mounted on said drilling bit in aposition to cooperate with corresponding bearing recesses in said mobiledrilling head to rigidly connect said mobile drilling head to saiddrilling bit.

4. Drilling apparatus as recited in claim 3 comprising a. an annularmember rigidly connected to said mobile drilling head and extending fora short distance upwardly therefrom around said casing;

b. a first ball bearing mounted in a first sealing positioned betweensaid casing and said mobile drilling head;

c. a second ball bearing mounted in a second sealing positioned betweensaid casing and said annular member; and

d. means of fluid communication connecting said first and secondsealings.

S. Drilling apparatus as recited in claim 3 wherein said casing has atleast one recess on the upper outer portion thereof for the attachmentof a base plate.

6. Drilling apparatus as recited in claim 3 wherein said means forcoupling the upper portion of said immobile casing to said pipe stringcomprise:

a. an annular assembly surrounding said casing and b. a verticaladjustment means comprising i. a threaded pipe;

ii. means for integrally connecting said threaded pipe to the upper endsaid pipe string;

iii. a castellated member supported by threaded pipe; and

iv. a threaded member which is threaded on said threaded pipe, attachedto said castellated memher, and attached to said annular assembly.

7. Drilling apparatus as recited in claim 6 wherein said threaded pipehas longitudinal grooves to receive the castellations on saidcastellated member.

8. Drilling apparatus as recited in claim 6 wherein said threaded memberis attached to said castellated member by means of bolts.

9. Drilling apparatus comprising:

1. a mobile drilling head having a series of consecutive recesses on theinner surface thereof, each of said consecutive recesses having a firstvertical edge, an inclined ramp extending upwardly from the firstvertical edge, and a second vertical edge opposing the first verticaledge and extending upwardly to the top of the inclined ramp of theadjacent recess;

2. an immobile casing extending upwardly from said mobile drilling head;

3. a drilling bit having a plurality of shoulders each of which isshaped to fit into one of the recesses in said mobile drilling head torigidly connect said mobile drilling head to said drilling bit;

4. a pipe string rigidly connected to said drilling bit and extendingupwardly through said immobile casing, and

5. means for coupling the upper portion of said immobile casing to saidpipe string,

said means for coupling the upper portion of said immobile casing tosaid pipe string comprise:

a. an annular assembly surrounding said casing and b. a verticaladjustment means comprising i. a threaded pipe; ii. means for integrallyconnecting said threaded pipe to the upper end of said pipe string;

said

positioned between said casing and said annular member; and

d. means of fluid communication connecting said first and secondsealings.

11. Drilling apparatus as recited in claim 9 wherein said threaded pipehas longitudinal grooves to receive the castellations on saidcastellated member.

12. Drilling apparatus as recited in claim 9 wherein said threadedmember is attached to said castellated member by means of bolts.

13. Drilling apparatus as recited in claim 9 wherein said casing has atleast one recess on the upper outer portion thereof for the attachmentof a base plate.

PATENT NO.

DATED INVENTOR(S) I 2 3,901,331 August 26, 1975 Branko Djur ovic It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

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Signed and Sealed this sixteenth Day of March 1976 A ttest:

RUTH C. MASON Arresting Officer C. MARSHALL DANN (mnmissr'uner ofParents and Trademarks

1. A support casing apparatus for a drilling head comprising a casing,wherein the head is connected to the casing by a bearing connectingmeans permitting free rotation of the head about its axis, first meansis provided for coupling the head to a lower portion of a rod stringcarrying a drilling tool to drive the head, the casing has at its upperportion second coupling means for rigidly attaching it to a pipe string,the second coupling means include a castellated member and in the pipestring includes a pipe with longitudinal grooves in which thecastellations of the castellated member are engaged, the rod beingattached at its lower portion to a stem supporting a turbine for drivinga drilling tool and at its upper portion to a joint of the upper portionof the rod string, the said joint being provided with a sleevecontrolled by a valve and with a pipe connected to and for causingunlocking of the second coupling means, such that operation of thesleeve causes release of the pipe string from the casing.
 1. a mobiledrilling head having a series of consecutive recesses on the innersurface thereof, each of said consecutive recesses having a firstvertical edge, an inclined ramp extending upwardly from the firstvertical edge, and a second vertical edge opposing the first verticaledge and extending upwardly to the top of the inclined ramp of theadjacent recess;
 2. an immobile casing extending upwardly from saidmobile drilling head;
 2. Apparatus as claimed in claim 1, wherein thecastellated member is rigidly attached to a means for locking thecastellated member on the grooved rod.
 3. Drilling apparatus comprising:a. a mobile drilling head having bearing recesses in its inner wall; b.an immobile casing extending upwardly from said mobile drilling head; c.a drilling bit; d. a pipe string rigidly connected to said drilling bitand extending upwardly through said immobile casing e. means forcoupling the upper portion of said immobile casing to said pipe string;f. a plurality of retractable arms mounted on said drilling bit in aposition to cooperate with corresponding bearing recesses in said mobiledrilling head to rigidly connect said mobile drilling head to saiddrilling bit.
 4. a pipe string rigidly connected to said drilling bitand extending upwardly through said immobile casing; and
 4. Drillingapparatus as recited in claim 3 comprising a. an annular member rigidlyconnected to said mobile drilling head and extending for a shortdistance upwardly therefrom around said casing; b. a first ball bearingmounted in a first sealing positioned between said casing and saidmobile drilling head; c. a second ball bearing mounted in a secondsealing positioned between said casing and said annular member; and d.means of fluid communication connecting said first and second sealings.5. Drilling apparatus as recited in claim 3 wherein said casing has atleast one recess on the upper outer portion thereof for the attachmentof a base plate.
 5. means for coupling the upper portion of saidimmobile casing to said pipe string, said means for coupling the upperportion of said immobile casing to said pipe string comprise: a. anannular assembly surrounding said casing and b. a vertical adjustmentmeans comprising i. a threaded pipe; ii. means for integrally connectingsaid threaded pipe to the upper end of said pipe string; iii. acastellated member supported by said threaded pipe; and iv. a threadedmember which is threaded on said threaded pipe, attached to saidcastellated member, and attached to said annular assembly.
 6. Drillingapparatus as recited in claim 3 wherein said means for coupling theupper portion of said immobile casing to said pipe string comprise: a.an annular assembly surrounding saiD casing and b. a vertical adjustmentmeans comprising i. a threaded pipe; ii. means for integrally connectingsaid threaded pipe to the upper end said pipe string; iii. a castellatedmember supported by said threaded pipe; and iv. a threaded member whichis threaded on said threaded pipe, attached to said castellated member,and attached to said annular assembly.
 7. Drilling apparatus as recitedin claim 6 wherein said threaded pipe has longitudinal grooves toreceive the castellations on said castellated member.
 8. Drillingapparatus as recited in claim 6 wherein said threaded member is attachedto said castellated member by means of bolts.
 9. Drilling apparatuscomprising:
 10. Drilling apparatus as recited in claim 9 and furthercomprising: a. an annular member rigidly connected to said mobiledriling head and extending for a short distance upwardly therefromaround said casing; b. a first ball bearing mounted in a first sealingpositioned between said casing and said mobile drilling head; c. asecond ball bearing mounted in a second sealing positioned between saidcasing and said annular member; and d. means of fluid communicationconnecting said first and second sealings.
 11. Drilling apparatus asrecited in claim 9 wherein said threaded pipe has longitudinal groovesto receive the castellations on said castellated member.
 12. Drillingapparatus as recited in claim 9 wherein said threaded member is attachedto said castellated member by means of bolts.
 13. Drilling apparatus asrecited in claim 9 wherein said casing has at least one recess on theupper outer portion thereof for the attachment of a base plate.